Thermodynamics of ion association. Part XX. Interpretation of the enthalpy changes

Abstract

Thermodynamic functions for the formation of a variety of metal complexes with nitrogen- and carboxylate oxygen containing ligands in aqueous solution have been analysed in terms of temperature-dependent and temperature-independent parts. A method for calculation of the temperature-independent component of the enthalpy change, ΔH_c, from the experimental data is described. The values are discussed in terms of M–N and M–O covalent interactions and also the specific steric requirements of different ligand molecules.